Outdoor landscaping wall systems such as retaining wall structures comprised of stacked and interlocked precast concrete building blocks are well known. It is common to vertically stack such blocks in horizontal courses, wherein an upper course is offset with respect to the next lower course, so as to provide a retaining wall having a desired inclination. Usually, such blocks are provided with grooves on their top and bottom faces. In this way, interlock connectors can be interposed between two stacked building blocks and fitted in the grooves.
An inconvenience of current wall systems is that the blocks need to interlocked as they are being stacked rather than locked after they are stacked.